I haven't changed anything in the suspension. I recently had my u-joints replaced. When I step on the gas from a stop it feels like the rear end has to break loose before I start moving. If I'm stopped and I let off the brake the truck begins to smoothly roll forward. As soon as I step on the gas I feel the rear break loose somewhere and then I'm on my happy way. When I come to a stop the sticking clunk happens again right as the vehicle rocks to a complete stop. Everything seems tight under there and the rear end makes no noise and shows no slop? I've had the wife start and stop 20 times while I walk along outside the truck. I can't pinpoint where the sticking clunk is taking place but you can kind of see the whole rear end jolt ever so slightly when she hits the gas or slams on the brakes.